A leveling agent for high optical parts such as a canopy, a preparation method and application thereof

Abstract

The application provides a preparation method of a leveling agent, comprising the following steps: mixing and reacting aliphatic isocyanate, functionalized ionic liquid, a first catalyst and a first solvent in a protective atmosphere to obtain the leveling agent. Compared with the prior art, the leveling agent prepared by the method has an amphiphilic structure, can quickly migrate to the surface of a wet film, forms a monolayer on the surface layer of the film, and utilizes the high surface tension to provide the power for leveling of the high-viscosity wet film, so that the leveling time of the coating can be reduced, the leveling time is close to the flow time or is less than the flow time, the contradictory requirement of the optical member on the flow time of the coating is solved, the prepared coating after coating has good leveling performance, and no light distortion is generated.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coatings, and particularly relates to a leveling agent suitable for high-optical cabin covers and a preparation method and application thereof. BACKGROUND

[0002] The function of the aircraft cabin cover is to seal the cabin and provide a comfortable and spacious activity space for the pilot, protect the pilot from the impact of high-speed airflow and external environment, and provide a good view for the pilot to complete various reconnaissance and combat tasks. Modern aircraft cabin covers are mostly made of optical plastic and are integrally formed. Compared with glass, they have many advantages, such as light weight, strong impact resistance, and low production cost. However, optical plastic also has obvious disadvantages: the texture of optical plastic is relatively soft, and it has poor scratch resistance. By coating a layer of wear-resistant polyurethane protective coating on the surface of the organic glass, the poor wear resistance and easy scratching of the optical plastic can be overcome.

[0003] However, as an optical part, the optical defect control of the protective coating of the cabin cover has very high requirements. The existence of optical defects such as flow marks causes optical distortion, which seriously affects the pilot's quick and accurate observation of the external environment and cannot effectively complete various operations and responses. Good optical leveling effect is a necessary condition for the application of the protective coating to the protection of the cabin cover.

[0004] At present, there is no optical coating specially prepared for large-size optical parts. The existing coating is coated on optical organic glass, especially on large-size complex curved surfaces, which is prone to optical defects such as flow marks, ripples, and more serious optical problems such as shrinkage, orange peel, and sagging. After the light passes through the optical defect coating, it deviates, causing optical distortion, which deforms the image and hinders the pilot's accurate judgment.

[0005] For curved optical coatings, the main problem at present is that the leveling time is longer than the flow time, and the coating cannot be leveled sufficiently, resulting in optical defects such as orange peel, ripples, and flow marks. To solve this problem, the flow time needs to be extended or the leveling time needs to be reduced. On the other hand, the optical coating requires rapid surface drying after coating to reduce the risk of dust embedding, and extending the flow time also increases the surface drying time. On the other hand, if the flow time is too long, the thickness of the prepared coating is insufficient, which cannot meet the use requirements of the protective coating, so the flow problem cannot be simply solved by extending the flow time. The existing leveling agent, silicone leveling agent, reduces the surface tension and has good wetting effect, but cannot provide sufficient leveling power for the high-viscosity wet film; and the higher the surface tension of the acrylic ester leveling agent, the higher the compatibility, which cannot quickly migrate to the surface of the wet film. The acrylic leveling agent that can quickly migrate has relatively low surface tension and cannot achieve good leveling effect. SUMMARY

[0006] Therefore, the present application aims to provide a leveling agent with amphiphilic structure and high surface tension for high optical parts such as cockpit covers, a preparation method and application thereof.

[0007] The present application provides a preparation method of a leveling agent for high optical parts such as cockpit covers, comprising the following steps:

[0008] The aliphatic isocyanate, the functionalized ionic liquid, the first catalyst and the first solvent are mixed and reacted in a protective atmosphere to obtain the leveling agent.

[0009] Preferably, the cation in the functionalized ionic liquid comprises one or more of hydroxyl, amino and carboxyl;

[0010] The first catalyst is selected from tertiary amine catalysts and / or organotin catalysts.

[0011] Preferably, the aliphatic isocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, HDI dimer and HDI trimer;

[0012] The functionalized ionic liquid is selected from one or more of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-aminethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-carboxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hydroxyethyl-3-methylimidazolium chloride, 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate, 1-hydroxyethyl-3-methylimidazolium hexafluorophosphate, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and hydroxyethyltrimethylammonium trifluoromethanesulfonate;

[0013] The tertiary amine catalyst is selected from one or more of triethylamine, diethylenetriamine, dimethylhexadecylamine, triethylenediamine, triethanolamine, methyldiethanolamine, dimethylethanolamine and pyridine;

[0014] The organotin catalyst is selected from one or more of dibutyltin dilaurate, stannous octoate and triethylenediamine.

[0015] Preferably, the mass ratio of the aliphatic isocyanate to the functionalized ionic liquid is 1:(1-3).

[0016] Preferably, the mass of the first solvent is 40%-60% of the total mass of the aliphatic isocyanate, the functionalized ionic liquid, the first catalyst and the first solvent;

[0017] The mass of the first catalyst is 0.01%-0.05% of the total mass of the aliphatic isocyanate, the functionalized ionic liquid, the first catalyst and the first solvent.

[0018] Preferably, the temperature of the reaction is 60-80℃; the time of the reaction is 2-10h.

[0019] The application further provides a leveling agent prepared by the preparation method.

[0020] The application further provides a polyurethane protective coating, comprising the leveling agent prepared by the preparation method.

[0021] Preferably, the polyurethane protective coating comprises component A and component B.

[0022] The component A comprises a polyol polymer, a chain extender, a second catalyst, a second solvent, the leveling agent and a light stabilizer.

[0023] The component B comprises an aliphatic diisocyanate.

[0024] Preferably, the mass of the leveling agent is 0.01%-0.05% of the mass of the polyurethane protective coating.

[0025] The application provides a preparation method of a leveling agent, comprising the following steps: mixing aliphatic isocyanate, functionalized ionic liquid, a first catalyst and a first solvent in a protective atmosphere to react, so as to obtain the leveling agent.

[0026] The experimental results show that the polyurethane protective coating prepared by using the leveling agent can be quickly leveled on the surface of a complex-curvature canopy cover, the prepared coating layer has no optical defects and no light distortion in the observation of a projection angle greater than 15°, and the optical problem of the protective coating applied to the canopy cover is solved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of the leveling agent obtained in Example 1 of the application.

[0028] Figure 2 FIG. 4 is a leveling effect diagram of the coating obtained in Examples 1-3 and Comparative Examples 1-2 of the application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0030] The present application provides a preparation method of a leveling agent for high optical parts such as a canopy, comprising the following steps: mixing and reacting aliphatic isocyanate, functionalized ionic liquid, first catalyst and first solvent in a protective atmosphere to obtain the leveling agent.

[0031] In the present application, there is no special limitation on the source of all raw materials, which can be commercially available.

[0032] In a specific embodiment provided by the present application, the aliphatic isocyanate preferably includes, but is not limited to, one or more of hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, HDI dimer and HDI trimer. The use of aliphatic isocyanate can prevent yellowing during use.

[0033] In a specific embodiment provided by the present application, the functionalized ionic liquid comprises a cation and an anion; the cation of the functionalized ionic liquid preferably comprises one or more of a hydroxyl group, an amino group and a carboxyl group; and the anion of the functionalized ionic liquid is preferably bis(trifluoromethanesulfonyl)imide; in the present application, most preferably, the functionalized ionic liquid includes, but is not limited to, one or more of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-aminethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-carboxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hydroxyethyl-3-methylimidazolium chloride, 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate, 1-hydroxyethyl-3-methylimidazolium hexafluorophosphate, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and hydroxyethyltrimethylammonium trifluoromethanesulfonate.

[0034] In a specific embodiment provided by the present application, the first catalyst is preferably a tertiary amine catalyst and / or an organic tin catalyst.

[0035] The tertiary amine catalyst can be any known to those skilled in the art, and there is no special limitation; in a specific embodiment provided by the present application, the tertiary amine catalyst is preferably one or more of triethylamine, diethylenetriamine, dimethylhexadecylamine, triethylenediamine, triethanolamine, methyldiethanolamine, dimethylethanolamine and pyridine.

[0036] The organic tin catalyst can be any organic tin catalyst known to those skilled in the art, and there is no particular limitation. In one specific embodiment provided in the present application, the organic tin catalyst is preferably one or more of dibutyltin dilaurate, stannous octoate and triethylenediamine.

[0037] In one specific embodiment provided in the present application, the mass ratio of the aliphatic isocyanate to the functionalized ionic liquid is preferably 1:(1-3), more preferably 1:(1.5-3); in some embodiments provided in the present application, the mass ratio of the aliphatic isocyanate to the functionalized ionic liquid is specifically 1:2, 1:1.5 or 1:3.

[0038] In one specific embodiment provided in the present application, the mass of the first catalyst is 0.01%-0.05% of the total mass of the aliphatic isocyanate, the functionalized ionic liquid, the first catalyst and the first solvent, preferably 0.01%-0.04%, more preferably 0.01%-0.03%, and more preferably 0.01%-0.02%.

[0039] In one specific embodiment provided in the present application, the first solvent can be any organic solvent known to those skilled in the art, and there is no particular limitation. In the present application, the first solvent preferably includes, but is not limited to, one or more of butyl acetate, cyclohexanone, dioxane and propylene glycol methyl ether propionate.

[0040] In one specific embodiment provided in the present application, the mass of the first solvent is 40%-60% of the total mass of the aliphatic isocyanate, the functionalized ionic liquid, the first catalyst and the first solvent, preferably 45%-55%, and more preferably 50%.

[0041] The aliphatic isocyanate, the functionalized ionic liquid, the first catalyst and the first solvent are mixed and reacted in a protective atmosphere to obtain the leveling agent. The protective atmosphere can be any protective atmosphere known to those skilled in the art, and there is no particular limitation. In the present application, the protective atmosphere is preferably nitrogen. The reaction temperature is preferably 60-80°C, more preferably 65-75°C, and more preferably 70°C. The reaction time is preferably 2-10h, more preferably 4-8h, more preferably 5-7h, and most preferably 6h.

[0042] The leveling agent prepared in the present application has an amphiphilic structure, can quickly migrate to the surface of a wet film, form a monolayer on the surface of the film, and provide the power for leveling of a high-viscosity wet film by using the high surface tension, thereby reducing the leveling time of the coating, making the leveling time close to or less than the flow time, solving the contradictory requirements of optical parts on the flow time of the coating, and making the prepared coating after coating have good leveling performance and not produce optical distortion.

[0043] The application also provides the leveling agent prepared by the preparation method.

[0044] In a specific embodiment provided by the application, the aliphatic isocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, HDI dimer and HDI trimer.

[0045] In a specific embodiment provided by the application, the functionalized ionic liquid preferably comprises a cation and an anion; the cation of the functionalized ionic liquid preferably comprises one or more of a hydroxyl group, an amino group and a carboxyl group; the functionalized ionic liquid preferably includes but is not limited to one or more of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-aminethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-carboxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hydroxyethyl-3-methylimidazolium chloride, 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate, 1-hydroxyethyl-3-methylimidazolium hexafluorophosphate, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and hydroxyethyltrimethylammonium trifluoromethanesulfonate.

[0046] In a specific embodiment provided by the application, the mass ratio of the aliphatic isocyanate to the functionalized ionic liquid is preferably 1:(1-3), more preferably 1:(1.5-3); in some embodiments provided by the application, the mass ratio of the aliphatic isocyanate to the functionalized ionic liquid is specifically 1:2, 1:1.5 or 1:3.

[0047] The application obtains a novel leveling agent by reacting a bifunctional or trifunctional isocyanate with a functionalized ionic liquid to cap all NCO groups, and the leveling agent has a large surface tension and is not completely miscible with a resin, so that a monolayer can be formed on a wet film surface to improve the flowability of the surface layer.

[0048] The application also provides a polyurethane protective coating, which comprises the leveling agent.

[0049] The leveling agent prepared by the application can improve the leveling power and the leveling effect, and can realize high leveling of a coating without prolonging the surface drying time of the coating or affecting the thickness of the coating.

[0050] In a specific embodiment provided by the application, the leveling agent preferably accounts for 0.01%-0.05% of the mass of the polyurethane protective coating, more preferably 0.02%-0.04%, more preferably 0.02%-0.03% and most preferably 0.02%.

[0051] In an embodiment of the present application, the polyurethane protective coating comprises a component A and a component B; the component A comprises a polyol polymer, a chain extender, a second catalyst, a second solvent, a leveling agent and a light stabilizer; the component B comprises an aliphatic diisocyanate.

[0052] The polyol polymer can be any known polyol polymer in the art without special limitation. In an embodiment of the present application, the polyol polymer preferably comprises, but is not limited to, one or more of polycaprolactone diol, polycarbonate and polyether polyol, more preferably polycaprolactone diol PCL210N.

[0053] In an embodiment of the present application, the mass of the polyol polymer is preferably 20% to 40%, more preferably 25% to 35%, even more preferably 28% to 35%, still more preferably 30% to 33%, most preferably 31% to 32% of the polyurethane protective coating. In some embodiments of the present application, the mass of the polyol polymer is specifically 31.56% of the polyurethane protective coating.

[0054] The chain extender can be any known chain extender in the art without special limitation. In an embodiment of the present application, the chain extender is preferably 1,2,4-butanetriol.

[0055] In an embodiment of the present application, the mass of the chain extender is preferably 1% to 5%, more preferably 1.5% to 4%, even more preferably 2% to 3%, still more preferably 2.3% to 2.6%, most preferably 2.4% to 2.5% of the polyurethane protective coating. In some embodiments of the present application, the mass of the chain extender is specifically 2.47% of the polyurethane protective coating.

[0056] The second catalyst can be any known catalyst in the art without special limitation. In an embodiment of the present application, the second catalyst is preferably a tertiary amine catalyst and / or an organic tin catalyst. The tertiary amine catalyst can be any known tertiary amine catalyst in the art without special limitation. In an embodiment of the present application, the tertiary amine catalyst is preferably one or more of triethylamine, diethylene triamine, dimethyl hexadecylamine, triethylene diamine, triethanolamine, methyl diethanolamine, dimethyl ethanolamine and pyridine. The organic tin catalyst can be any known organic tin catalyst in the art without special limitation. In an embodiment of the present application, the organic tin catalyst is preferably one or more of dibutyl tin dilaurate, stannous octoate and triethylene diamine.

[0057] In one specific embodiment provided by the present application, the mass of the second catalyst is preferably 0.01% to 2%, more preferably 0.01% to 1.5%, still more preferably 0.02% to 1%, yet more preferably 0.02% to 0.5%, yet more preferably 0.02% to 0.1%, yet more preferably 0.02% to 0.05%, and most preferably 0.03% of the polyurethane protective coating.

[0058] The light stabilizer can be any light stabilizer known to those skilled in the art, and is not particularly limited, and in the present application, Tinuvin 770 is preferred.

[0059] In one specific embodiment provided by the present application, the mass of the light stabilizer is preferably 0.1% to 1%, more preferably 0.3% to 0.8%, still more preferably 0.4% to 0.6%, and most preferably 0.5% of the polyurethane protective coating.

[0060] The second solvent can be any organic solvent known to those skilled in the art, and is not particularly limited, and in the present application, butyl acetate and N,N-dimethylformamide are preferred; the mass of the butyl acetate and N,N-dimethylformamide is preferably 1:(1 to 2), more preferably 1:(1.3 to 1.8), still more preferably 1:(1.4 to 1.6), and most preferably 1:1.5.

[0061] In one specific embodiment provided by the present application, the second solvent is preferably 40% to 60%, more preferably 45% to 55%, still more preferably 48% to 52%, and most preferably 49% to 50% of the polyurethane protective coating.

[0062] In another specific embodiment provided by the present application, the A component preferably further comprises a wetting agent; the type of the wetting agent can be any wetting agent known to those skilled in the art, and is not particularly limited, and in the present application, a silicone wetting agent is preferred, and more preferably, Silok-8035 is preferred; the mass of the wetting agent is preferably 0.01% to 0.05%, more preferably 0.02% to 0.04%, still more preferably 0.02% to 0.03%, and most preferably 0.02% of the polyurethane protective coating.

[0063] In another specific embodiment provided by the present application, the A component preferably further comprises an antioxidant; the type of the antioxidant can be any antioxidant known to those skilled in the art, and is not particularly limited, and in the present application, Irganox 1010 is preferred; the mass of the antioxidant is preferably 0.1% to 1%, more preferably 0.2% to 0.8%, still more preferably 0.2% to 0.6%, yet more preferably 0.2% to 0.4%, yet more preferably 0.2% to 0.3%, and most preferably 0.25% of the polyurethane protective coating.

[0064] In another specific embodiment provided by the present application, the A component preferably further comprises an ultraviolet absorber; the type of the ultraviolet absorber can be any ultraviolet absorber known to those skilled in the art without special limitation, and preferably UV-328 in the present application; the mass of the ultraviolet absorber is preferably 0.1% to 1% of the mass of the polyurethane protective coating, more preferably 0.2% to 0.8%, further preferably 0.2% to 0.6%, further preferably 0.2% to 0.4%, further preferably 0.2% to 0.3%, and most preferably 0.25%.

[0065] The aliphatic diisocyanate can be any aliphatic diisocyanate known to those skilled in the art without special limitation, and preferably includes but is not limited to one or more of the trimer of hexamethylene diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

[0066] In one specific embodiment provided by the present application, the mass of the aliphatic diisocyanate is preferably 10% to 20% of the mass of the polyurethane protective coating, more preferably 12% to 18%, further preferably 14% to 16%, and most preferably 15% to 16%; in some embodiments of the present application, the mass of the aliphatic diisocyanate is specifically 15.52% of the mass of the polyurethane protective coating.

[0067] The present application also provides a preparation method of the above-mentioned polyurethane protective coating, comprising the following steps: mixing the A component and the B component, filtering, and standing to obtain the polyurethane protective coating; the mixing method can be any method known to those skilled in the art without special limitation, and preferably stirring in the present application; the mixing time is preferably 10 to 60 min, more preferably 20 to 50 min, further preferably 25 to 40 min, and most preferably 30 min; the filtering is preferably positive pressure filtering; and the standing time is preferably 10 to 60 min, more preferably 20 to 50 min, further preferably 25 to 40 min, and most preferably 30 min.

[0068] The present application also provides an application of the above-mentioned polyurethane protective coating as an optical coating.

[0069] The present application also provides an application of the above-mentioned polyurethane protective coating as a protective coating of a canopy.

[0070] The polyurethane protective coating provided by the present application is used in one of a lens, a car, or a high-speed rail glass protection, etc. with high requirements on optical properties.

[0071] In order to further illustrate the present application, the following embodiments provide a leveling agent suitable for high optical parts such as cockpit covers, a preparation method and application thereof.

[0072] The reagents used in the following examples are commercially available.

[0073] Example 1

[0074] The preparation method of the optical leveling polyurethane protective coating includes:

[0075] Step one: preparing the leveling agent, the raw materials include, by weight fraction: hexamethylene diisocyanate 16.81%, 1-hydroxyethyl-3-methyl imidazole bis(trifluoromethane sulfonate) imidate salt 33.18%, cyclohexanone 50%, dibutyltin dilaurate 0.01%, placing the above raw materials in a reaction bottle at 70°C, nitrogen protection, stirring for 6h, obtaining the leveling agent.

[0076] The obtained leveling agent is analyzed by nuclear magnetic resonance, and the nuclear magnetic resonance hydrogen spectrum thereof is shown in Figure 1 .

[0077]

[0078] Step two: applying the leveling agent to the polyurethane protective coating, the raw materials include, by weight fraction: polycaprolactone dihydric alcohol (PCL210N) 31.56%, 1,2,4-butanetriol 2.47%, catalyst dibutyltin dilaurate 0.03%, leveling agent obtained in step one 0.02%, wetting agent Silok-8035 0.02%, antioxidant Irganox1010 0.25%, ultraviolet absorber UV-328 0.25%, light stabilizer Tinuvin770 0.25%, butyl acetate 19.82%, N,N dimethylformamide 29.81%, isophorone diisocyanate 15.52%.

[0079] Step three: mixing the components in step two except isophorone diisocyanate, then pouring into a stirring reaction kettle with isophorone diisocyanate, controlling the temperature at 20°C for 2h, standing for 30min to remove bubbles, coating the coating on organic glass in a vertical manner at 20°C environment, leveling and drying for 2-6h, then transferring the product to a blast drying oven at 70°C for 12h.

[0080] Example 2

[0081] Step one: preparing the leveling agent, the raw materials include, by weight fraction: dicyclohexyl methane diisocyanate 22.3%, 1-hydroxyethyl-3-methyl imidazole chloride salt 27.68%, butyl acetate 50%, dibutyltin dilaurate 0.02%, placing the above raw materials in a reaction bottle at 70°C, nitrogen protection, stirring for 6h, obtaining the leveling agent.

[0082]

[0083] Step two: the leveling agent is applied to the polyurethane protective coating, and the raw materials include, by weight fraction: polycaprolactone diol (PCL210N) 31.56%, 1,2,4-butanetriol 2.47%, catalyst dibutyltin dilaurate 0.03%, leveling agent obtained in step one 0.02%, wetting agent Silok-8035 0.02%, antioxidant Irganox1010 0.25%, ultraviolet absorber UV-328 0.25%, light stabilizer Tinuvin770 0.25%, butyl acetate 19.82%, N,N dimethylformamide 29.81%, isophorone diisocyanate 15.52%.

[0084] Step three: mix the components of step two except isophorone diisocyanate, then pour into a stirred reaction kettle with isophorone diisocyanate, control temperature 20℃, react for 2h, stand for 30min to remove bubbles, coat the coating on organic glass using vertical spraying in a 20℃ environment, level and dry for 2-6h, then transfer the product to a forced air drying oven at 70℃ for 12h.

[0085] Example 3

[0086] Step one: prepare the leveling agent, and the raw materials include, by weight fraction: HDI trimer 19.943%, hydroxyethyltrimethylammonium trifluoromethanesulfonate 30.05%, butyl acetate 50%, dibutyltin dilaurate 0.02%, place the above raw materials in a reaction bottle, 70℃, nitrogen protection, stir for 6h, obtain the leveling agent.

[0087]

[0088] Step two: the leveling agent is applied to the polyurethane protective coating, and the raw materials include, by weight fraction: polycaprolactone diol (PCL210N) 31.56%, 1,2,4-butanetriol 2.47%, catalyst dibutyltin dilaurate 0.03%, leveling agent obtained in step one 0.02%, wetting agent Silok-8035 0.02%, antioxidant Irganox1010 0.25%, ultraviolet absorber UV-328 0.25%, light stabilizer Tinuvin770 0.25%, butyl acetate 19.82%, N,N dimethylformamide 29.81%, isophorone diisocyanate 15.52%.

[0089] Step three: mix the components of step two except isophorone diisocyanate, then pour into the stirred reaction kettle with isophorone diisocyanate, control temperature 20℃ reaction 2h, stand for 30min to remove bubbles, use vertical face shower coating method to coat the paint on the organic glass at 20℃ environment, level dry 2-6h, then transfer the product to the air drying oven 70℃ curing 12h.

[0090] Comparative example 1

[0091] Commercially available acrylate leveling agent BYK354 is applied to polyurethane protective coating, the raw materials include by weight fraction: polycaprolactone diol (PCL210N) 31.56%, 1,2,4-butanetriol 2.47%, catalyst dibutyltin dilaurate 0.03%, BYK254 leveling agent 0.02%, wetting agent Silok-8035 0.02%, antioxidant Irganox1010 0.25%, ultraviolet absorber UV-328 0.25%, light stabilizer Tinuvin770 0.25%, butyl acetate 19.82%, N,N dimethylformamide 29.81%, isophorone diisocyanate 15.52%.

[0092] Step three: mix the components of step two except isophorone diisocyanate, then pour into the stirred reaction kettle with isophorone diisocyanate, control temperature 20℃ reaction 2h, stand for 30min to remove bubbles, use vertical face shower coating method to coat the paint on the organic glass at 20℃ environment, level dry 2-6h, then transfer the product to the air drying oven 70℃ curing 12h.

[0093] Comparative example 2

[0094] Commercially available silicone leveling agent BYK333 is applied to polyurethane protective coating, the raw materials include by weight fraction: polycaprolactone diol (PCL210N) 31.56%, 1,2,4-butanetriol 2.47%, catalyst dibutyltin dilaurate 0.03%, BYK333 leveling agent 0.02%, wetting agent Silok-8035 0.02%, antioxidant Irganox1010 0.25%, ultraviolet absorber UV-328 0.25%, light stabilizer Tinuvin770 0.25%, butyl acetate 19.82%, N,N dimethylformamide 29.81%, isophorone diisocyanate 15.52%.

[0095] Step three: mix the components of step two except isophorone diisocyanate, then pour into the stirred reaction kettle with isophorone diisocyanate, control temperature 20℃ reaction 2h, stand for 30min to remove bubbles, in 20℃ environment, the coating is coated on the organic glass by vertical surface pouring, leveling and dry 2-6h, then transfer the product to the air drying oven 70℃ curing 12h.

[0096] Figure 2 The leveling effect figures (slide 30° angle projection photos) of the coatings obtained in examples 1-3 and comparative examples 1-3, wherein (a) is example 1, (b) is example 2, (c) is example 3, (d) is comparative example 1, (e) is comparative example 2.

[0097] Table 1 is the statistical results of the leveling effect of the coatings obtained in examples 1-3 and comparative examples 1-3.

[0098] Table 1 performance and leveling state of examples and comparative examples

[0099] Transmittance (PMM substrate) Adhesion Haze increase after Taber 100 stroke treatment Leveling state Example 1 92.12％ 5B 0.36％ Leveling Example 2 92.08％ 5B 0.42％ Leveling Example 3 92.04％ 5B 0.44％ Leveling Comparative Example 1 92.06％ 5B 0.35％ Light flow marks Comparative Example 2 92.05％ 5B 0.38％ Severe flow marks

[0100] The above only is the preferred embodiment of the present application, it should be pointed out, for the ordinary skilled in the art, without departing from the principles of the present application, can also make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for preparing a leveling agent suitable for high optical parts, characterized in that: The following steps are involved: Mixing and reacting aliphatic isocyanate, functionalized ionic liquid, a first catalyst and a first solvent in a protective atmosphere to obtain a leveling agent; The first catalyst is selected from tertiary amine catalysts and / or organotin catalysts; The aliphatic isocyanate is selected from HDI trimer and / or 4,4'-dicyclohexylmethane diisocyanate; The functionalized ionic liquid is selected from one or more of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hydroxyethyl-3-methylimidazolium chloride, 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate, 1-hydroxyethyl-3-methylimidazolium hexafluorophosphate, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and hydroxyethyltrimethylammonium trifluoromethanesulfonate.

2. The preparation method according to claim 1, characterized in that The tertiary amine catalyst is selected from one or more of triethylamine, diethylenetriamine, dimethylhexadecylamine, triethylenediamine, triethanolamine, methyldiethanolamine, dimethylethanolamine and pyridine; The organotin catalyst is selected from one or more of dibutyltin dilaurate, stannous octoate and triethylenediamine.

3. The preparation method according to claim 1, characterized in that The mass ratio of the aliphatic isocyanate to the functionalized ionic liquid is 1:(1-3).

4. The preparation method according to claim 1, characterized in that The mass of the first solvent is 40% to 60% of the total mass of the aliphatic isocyanate, the functionalized ionic liquid, the first catalyst and the first solvent; The mass of the first catalyst is 0.01% to 0.05% of the total mass of the aliphatic isocyanate, the functionalized ionic liquid, the first catalyst and the first solvent.

5. The preparation method according to claim 1, characterized in that The reaction temperature is 60° C. to 80° C., and the reaction time is 2 to 10 h.

6. A leveling agent prepared by the preparation method according to any one of claims 1 to 5, characterized in that: It is formed by the reaction of aliphatic isocyanates with functionalized ionic liquids.

7. A polyurethane protective coating, characterized in that: A leveling agent prepared by the preparation method according to any one of claims 1 to 6.

8. The polyurethane protective coating according to claim 7, characterized in that: The polyurethane protective coating comprises component A and component B; The component A includes a polyol polymer, a chain extender, a second catalyst, a second solvent, a leveling agent and a light stabilizer; The B component includes an aliphatic diisocyanate.

9. The polyurethane protective coating according to claim 8, characterized in that The mass of the leveling agent is 0.01% to 0.05% of the mass of the polyurethane protective coating.

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